Symptoms are typical of damage from herbicide drift. Have you or your neighbors been spraying for weeds?
I've even seen this happen when using a dry weed and feed in lawns. As the granules in the lawn release their chemicals in gaseous form, nearby plants can be affected. Tomatoes are incredibly sensitive.

Ditto what Leftwood said, it looks to be the beginning symptoms of a broadleaf herbicide. This is showing up more and more in my area where people use straw as mulch in their gardens. Have you mulched with anything?